When a cancer antigen that is specific to a cancer cell is present on the surface of the cancer cell, there are times when an innate immune reaction as a result of the cancer cell being recognized as a substance foreign to oneself proceeds, and a specific immune response is subsequently induced to thus cause a reaction to eliminate the cancer cell.
When a specific immune response is induced, cancer cell-derived fragments and the like in body fluids are eliminated by neutralizing antibodies, and the cancer cells themselves are eliminated by cytotoxic T lymphocytes (CTLs). That is, the CTL specifically recognizes a cancer antigen (CTL epitope) consisting of 8 to 11 amino acids presented in an HLA class I molecule on the surface of a cancer cell, and eliminates the cancer by damaging the cancer cell. Therefore, it is critical to identify such a cancer-specific CTL epitope in order to develop a therapeutic vaccine for the cancer.
A technique of this kind is known from Patent Publication 1. Patent Publication 1 states that an oligopeptide formed from a specific amino acid sequence has the property of binding to an HLA.
[Patent Publication 1] Japanese Patent Application Laid-open No. H8-151396 (1996)